Ring and bar tensioner

ABSTRACT

A tensioning apparatus that includes a housing through which a threadline passes in a straight path. The housing contains a plurality of rings suspendable from the threadline and maintains these rings for free movement in a plane oriented at tilt and skew angles with respect to the threadline of from about 5* to about 45*.

United States Patent Griggs, Jr. et al. 51 July 25, 1972 s41 RING ANDBAR TENSIONER [56] Relerences Cited [72] Inventors: Ernest Lee Griggs,Jr., Chattanooga; John UNITED STATES PATENTS David bmh 3,582,012 6/l97lCocker ..242/154 [73] Assignee: E. I. du Pont de Nemours and Company,

Wilmington, Del. Primary Examiner-Stanley N. Gilreath t, Filed: Dec.1969 Attorney Howard? Wes Jr 211 Appl. No.: 885,854 {57] ABSTRACT Atensioning apparatus that includes a housing through which 52 us. c1..242/153, 242/154 a "Headline Passes in a Straight P The housingcontains a 511 1111.01 ..B65h 59/34 plurality of rings suspendable fromthe threadline and 53 Field ofSearch ..242/153, 154, 147 wins theserings for free movement in a plane oriented at tilt and skew angles withrespect to the threadline of from about 5 to about 45.

INVENTORS ERNEST LEE GRIGGS,JR.

JOHN DAVID PORTER ATTORNEY RING AND BAR TENSIONER BACKGROUND OF THEINVENTION This invention concerns a tensioning device and moreparticularly a device of the ring and bar type for maintaining a uniformtension on moving yarns. The device is particularly suitable for use inhigh speed textile operations such as yarn beaming. Yarn tensioningdevices are known which consist of a series of horizontal, parallelguide pins across which the yarn passes and rings suspended by the yarnhanging between the pins. The number and weight of the rings suspendedby the yarn determines the yarn tension delivered. Such known devicesare suitable for controlling tension on yarns moving at relatively lowspeeds, such as on knitting machines. On yarns moving at high speedsfrom a supply package which tends to deliver the yarn under variabletension, such devices are found to give inadequate tension control dueto vibration or chattering of the rings caused by tension variations inthe feed yarn. In addition the rings are subject to wear atsubstantially only one area on the yarn contact surface.

Accordingly, an object of this invention is a tension device of thealternating suspended ring and bar type which provides tension controlsuitable for use in high speed yarn beaming operations. Other objectsare a tensioning device which provides positive control and containmentof the yarn at all times while running and during stops and starts,longer life and ease of changing from one tension level to another.

SUMMARY OF THE INVENTION The invention is a yarn tensioning devicecomprised of two opposed vertical end means with circular yarn guidemeans defining a yarn path therebetween; said end means connected by twoopposing vertical parallel sides; a plurality of parallel yarn guidepins connecting said sides, said pins defining a plane substantiallyadjacent to and parallel with said yarn path; said guide pinsinterspaced with a plurality of parallel rings suspendable from a yarnpassing through said device; the planes of said rings being maintainedsubstantially parallel to the axes of said guide pins, but said planesbeing tilted by an angle of from about 5 to 45 from a vertical lineperpendicular to said threadline path by opposing straight channels insaid sides between said guide pins.

Another embodiment is the above device wherein the axes of said pins andsaid ring planes are skewed at an angle of from about 5 to 45 withrespect to a horizontal line perpendicular to said yarn path.

In a preferred embodiment, the planes of the rings in said device aremaintained by said channels at a tilt angle of from about to 30 and askew angle of from about 5 to as described.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top view of a tensioningdevice of this invention. FIG. 2 is a side view ofthe same device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG.1, a housing 10 is formed from integral side and end pieces 11 and I2joined at each end to support circular yarn inlet guide 13 and outletguide 14 which define the yarn path 15 through the device. Sides 11 and12 are connected by and provide support for parallel guide pins [6.Sides 11 and 12 contain inwardly facing straight channels 18, thechannels on opposing sides being displaced such that the planes oftensioning rings 17 are skewed by angle a with respect to a horizontalline perpendicular to yarn path 15. A mounting bracket supports housing10.

FIG. 2 shows side 12 having channels 18 on its inside surface, saidchannels being tilted in the direction of movement in yarn path 15 by anangle b with respect to a line perpendicular to yarn path 15. Thechannels 18 are interspaced by guide pins 16. A movable ring keeper pin19 is supported by the ends of the device. The ring keeper pin 19 servesas a rest for rings in channels 18 when in an inactive raised position.

The essential and novel feature of this invention is the use of channelsin the sides of the tensioner to substantially contain free movement ofthe rings in all but a sloped vertical direction. The use-of suchchannels to maintain the planes of the rings at an angle tilted fromabout 5 to 45 preferably 5 to 30 with respect to a line vertical to theyarn path results in a reduction of ring chatter at high yarn speeds;such chatter being caused by variations in tension of the feed yarn.Reduction or elimination of such chatter results in more uniform tensioncontrol.

Placement of the channels so as to orient the planes of the rings at askew angle of 5 to 45 preferably 5 to 15 with respect to a horizontalline perpendicular to the yarn path results in rotation of the ringsduring use such that localized wear on the yarn contact surface of therings is eliminated leading to longer ring life.

The particular tilt and skew angles necessary for desired operation isdependent in each case upon the uniformity of tension on the feed yarn,frictional coefficient of the tensioner body material with the ringmaterial in the channels, frictional coefficient between the rings andthe particular yarn and clearance between the channels and the rings.

In use, the tension device of this invention preferably is oriented withrespect to yarn travel such that the plane of the rings is tilted froma'vertical position, in the direction of yarn travel, that is, the topsof the channels are displaced with respect to the bottom end thereof inthe direction that the yarn is moving.

The device may be constructed of any suitable materials. The yarncontacting surfaces (end guides, guide pins, rings) are preferablyconstructed of, or at least coated with, known ceramic materials forlong wear. The end and channeled side pieces are convenientlyconstructed of durable plastic materials such as general purposepolystyrene. Where desired, dampening or elimination of ring chatterduring operation can be realized through the use of a rubber orrubber-like material with a high coefficient of friction for thetensioner body. For example, a 50 Shore A hardness rubber body givessignificantly more dampening than a methylmethacrylate body.

Yarn tension control and confinement is maintained by threading the yarnthrough the eyelets and rings above the guide pins. The number andweight of rings employed will determine the tension level attained.Preferably the device contains at least two rings and at least threeguide pins. Any number of rings and bars to attain the tension andcontrol desired may be employed. The rings may have a circular orpolygonal cross-section although a circular yarn contacting innersurface is preferred.

Control of the yarn during stoppage is maintained by the rings droppinglower between the bars thereby increasing yarn frictional drag as theangle of wrap is increased around the rings and bars. Since verticallyoriented rings tend to drop and brake the yarn more quickly than thetilted rings when the yarn is stopped, the apparatus may include a minornumber of vertically oriented rings, in addition to the tilted rings,when faster braking of the yarn is desired to avoid slack in the stoppedyarn. Since the yarn is contained within the rings, there is no chancefor yarn to become unthreaded.

All the rings in a device do not need to be employed during use. Theycan be held out of action in a known manner by the use of a movablekeeper pin or bar 19 inserted between the ends such that the rings areheld up out of contact with the yarn. The ring keeper can be insertedsuch that the yarn passes through the rings while they are being heldabove the yarn but remain in a threaded position ready for action asneeded.

Although the illustrated embodiment shows the rings and bars alternatelyspaced throughout the device. This spacing is not essential foreffective operation. For example, if the rings at each end of thehousing 10 are the only rings actively engaging the yarn then everyother guide bar between the rings could be removed without affectingoperation and there are other similar spacing relationships that may beemployed.

A tension device of the type shown in the figures, having a ring tiltangle of 25 and a skew angle of as defined herein, provided tensioncontrol of 3.5 i 0.1 grams during the beaming of 30 denier, lO-filamentnylon yarns at 600 ypm. using three one gram rings and of 5.0 l.5 gramsduring the beaming of 70 denier, 34-filament nylon yarn at 600 ypm.,using four 1 gram rings.

What is claimed is:

l. A threadline tensioning apparatus including; a housing formed ofparallel ends joined to each other by opposed parallel sides said endshaving guide means for passing a threadline therethrough in a straightpath; a plurality of guide pins connected between said sides below saidpath; a plurality of rings positioned in said housing in a spacedrelationship to each other and suspendible from a threadline passingthrough the housing; the improvement comprising: a plurality of pairs ofopposed inwardly facing channels in said sides, each pair maintainingtherebetween a ring for free movement in a plane with respect to thethread-line, said plane being at a tilt angle of from about 5 to about45 from a vertical line perpendicular to said path, said plane beingskewed at an angle of from about 5 to about 45 with respect to ahorizontal line perpendicular to said path.

2. The apparatus as defined in claim 1 said tilt angle being from about10 to about 30, said plane being skewed at an angle of from about 5 toabout 15.

3. A threadline tensioning apparatus including; a housing formed ofparallel ends joined to each other by opposed parallel sides, said endshaving guide means for passing a threadline therethrough in a straightpath; a plurality of guide pins connected between said sides below saidpath; a plurality of rings positioned in said housing in a spacedrelationship to each other and suspendible from a threadline passingthrough the housing; the improvement comprising: a plurality of pairs ofopposed inwardly facing channels in said sides, each pair maintainingtherebetween a ring for free movement in a plane with respect to thethreadline, said plane being skewed at an angle of from about 5 to about45 with respect to a horizontal line perpendicular to said path.

4. The apparatus as defined in claim 3, said plane being skewed at anangle of from about 5 to about 15.

1. A threadline tensioning apparatus including; a housing formed ofparallel ends joined to each other by opposed parallel sides said endshaving guide means for passing a threadline therethrough in a straightpath; a plurality of guide pins connected between said sides below saidpath; a plurality of rings positioned in said housing in a spacedrelationship to each other and suspendible from a threadline passingthrough the housing; the improvement comprising: a plurality of pairs ofopposed inwardly facing channels in said sides, each pair maintainingtherebetween a ring for free movement in a plane with respect to thethread-line, said plane being at a tilt angle of from about 5* to about45* from a vertical line perpendicular to said path, said plane beingskewed at an angle of from about 5* to about 45* with respect to ahorizontal line perpendicular to said path.
 2. The apparatus as definedin claim 1 said tilt angle being from about 10* to about 30*, said planebeing skewed at an angle of from about 5* to about 15*.
 3. A threadlinetensioning apparatus including; a housing formed of parallel ends joinedto each other by opposed parallel sides, said ends having guide meansfor passing a threadline therethrough in a straight path; a plurality ofguide pins connected between said sides below said path; a plurality ofrings positioned in said housing in a spaced relationship to each otherand suspendible from a threadline passing through the housing; theimprovement comprising: a plurality of pairs of opposed inwardly facingchannels in said sides, each pair maintaining therebetween a ring forfree movement in a plane with respect to the threadline, said planebeing skewed at an angle of from about 5* to about 45* with respect to ahorizontal line perpendicular to said path.
 4. The apparatus as definedin claim 3, said plane being skewed at an angle of from about 5* toabout 15* .